A current transformer apparatus is configured to enable it to be electrically connected with and physically mounted to a circuit board. The current transformer apparatus includes a support upon which a coil is situated and upon which a plurality of approximately U-shaped electrical connectors are also situated. The electrical connectors each include an electrical contact that is biased toward a reaction structure. A circuit board is received between the electrical contact and the reaction structure, and the bias between the electrical contact and the reaction structure mounts current transformer apparatus to the circuit board and provides an electrical connection therebetween

A current measurement system is configured to measure an alternating-current (AC) current flowing through a conductor. The AC current has a frequency within a measurement range. The system includes a current sensor and a shunt resistor. The current sensor includes a measurement coil configured to be magnetically coupled to the conductor. The shunt resistor has both ends electrically connected to both ends of the measurement coil, respectively. An output voltage across the both ends of the shunt resistor is saturated at a saturation point in a saturation frequency of the frequency of the AC current. An upper limit value of the measurement range including the frequency is higher than a fundamental frequency of the AC current. The saturation frequency is higher than or equal to the upper limit value. The current measurement system improves sensitivity to frequency components higher than the fundamental frequency of the AC current.

An energy harvesting device (CTH) installed in an electrical distribution system (EDS) for powering ancillary electrical devices (AD) used in the distribution system. The device includes a first voltage regulator circuit (CC) configured to produce a voltage matched to a power curve of a current transformer (CT) to which the device is electrically coupled. The device also includes a second and separate voltage regulator circuit (SVR) which continuously operates to maximize the amount of electrical energy recovered from the current transformer.

A current transformer includes a closed magnetic circuit and a secondary winding. A first part of the closed magnetic circuit completely surrounds a primary conductor, and a second part of the closed magnetic circuit forms the secondary winding. The second part of the closed magnetic circuit serves as a magnetic core of the secondary winding. The closed magnetic circuit forms a plurality of branch magnetic circuits at the second part, and a secondary winding is formed on each branch magnetic circuit. Each branch magnetic circuit serves as a magnetic core of a corresponding secondary winding. Each secondary winding is staggered with each other in at least one of the length, the height and the thickness.

A terminal shield for a circuit breaker, formed of an electrically insulating material, protects an operator from inadvertently touching the load terminal that would otherwise be exposed on the bottom side of the circuit breaker: In accordance with an example embodiment of the invention, the terminal shield is integrated with a toroidally shaped current transformer sensor, to enable measuring the current in a load wire that has been inserted through an aperture in the terminal shield. Preferably there is an access hole in the front portion of the terminal shield, which allows the operator to insert a tool through the front face of the circuit breaker, to tighten the load terminal onto the load wire. The terminal shield with the integrated current transformer sensor enables standardization of load current sensing capability for circuit breakers and further enables ease of installation without clutter in the confined regions of the load center.

A sensor for measuring current flow includes a power generation circuit, a current measurement circuit and a microcontroller. The power generation circuit includes a current transformer that harvests energy from a load applied to the conductor and uses the harvested energy to power the current measurement circuit and microcontroller. The current measurement circuit includes a Hall effect sensor that outputs a voltage signal in response to detecting a magnetic flux generated by the flow of current through the conductor. The microcontroller calculates a current measurement based on the voltage signal received from the current measurement system. The Hall effect sensor is able to generate the voltage signal used to measure current flow at the same time that the current transformer harvests energy from the current flowing through the conductor. A fault detection system is able to alert a user to problems with the current transformer and/or the Hall effect sensor.

A sensor for measuring current flow includes a power generation circuit, a current measurement circuit and a microcontroller. The power generation circuit includes a current transformer that harvests energy from a load applied to the conductor and uses the harvested energy to power the current measurement circuit and microcontroller. The current measurement circuit includes a Hall effect sensor that outputs a voltage signal in response to detecting a magnetic flux generated by the flow of current through the conductor. The microcontroller calculates a current measurement based on the voltage signal received from the current measurement system. The Hall effect sensor is able to generate the voltage signal used to measure current flow at the same time that the current transformer harvests energy from the current flowing through the conductor. A fault detection system is able to alert a user to problems with the current transformer and/or the Hall effect sensor.

A support for mounting an accessory equipment assembly with one or more accessory equipment units, such as current transformer units, to a base of a bushing includes a conductor surrounded by an insulator part such that each of the accessory equipment units is positioned in a defined way regarding the conductor, wherein said support includes aligning means for aligning each individual accessory equipment unit separately with respect to the conductor. A corresponding accessory equipment module includes an accessory equipment assembly with one or more accessory equipment units such as current transformer units, and a support for mounting the accessory equipment assembly as well as a bushing unit including a bushing and said kind of accessory equipment module.

A support for mounting an accessory equipment assembly with one or more accessory equipment units, such as current transformer units, to a base of a bushing includes a conductor surrounded by an insulator part such that each of the accessory equipment units is positioned in a defined way regarding the conductor, wherein said support includes aligning means for aligning each individual accessory equipment unit separately with respect to the conductor. A corresponding accessory equipment module includes an accessory equipment assembly with one or more accessory equipment units such as current transformer units, and a support for mounting the accessory equipment assembly as well as a bushing unit including a bushing and said kind of accessory equipment module.

A smart current transformer for determining primary current or power consumption, by stepping down the primary current to a secondary current for subsequent measurement by a connected meter. The current transformer is provided with a connected non-volatile memory for storing calibration data (and optionally identification data) regarding that particular current transformer. The calibration data can include the gain error and/or phase delay for the current transformer, as determined from prior calibration testing of the current transformer. The calibration data may be communicated to or otherwise determined by the meter, and used to calibrate the measurement of the secondary current, in order to determine the primary current or power consumption. Also disclosed is a system and method utilizing such a smart current transformer.